The Department of Pediatric at Baylor College of Medicine (BCM) and University of Texas Medical School at Houston (UT) intend jointly to become a National Heart, Lung, and Blood Institute (NHLBI)-funded evaluation unit for the lung and cardiac complications of pediatric HIV infection with UT as the subcontractor; the Departments of Obstetrics (OB) and BCM and UT and the Department of Pathology at BCM will also participate. These operations will be accomplished by use of centralized BCM facilities located at Texas Children's Hospital -- Clinical Research Center (CRC). The NHLBI proposal will interact with several National Institutes of Health (NIH)- funded pediatric AIDS research protocols, either active or pending, which utilize the CRC and which involve both BCM and UT in a similar contractor-subcontractor relationship. The present NHLBI proposal will utilize OB departments at BCM and UT which will insure that every infant born to a high-risk mother (intravenous drug abuser, carrier of sexually- transmitted diseases, carrier of hepatitis B) in the city of Houston will be enrolled. In addition to infants at risk for HIV infection entering the NHLBI project through the OB intake system, children already identified with HIV infection, some of which will be on NIH treatment protocols, will be available for entry into the NHLBI study. Crucial for the assessment of clinical measurements of lung and heart function is the tissue correlation provided by the Department of Pathology, both biopsy and autopsy examinations. Equally important is the correlation between clinical measurements of lung and heart function and the presence of intercurrent or secondary viral infection, as will be provided by surveillance viral cultures and the use of viral gene probes. Also, simultaneous immunologic measurements of T lymphocyte subsets, lymphocyte proliferation to mitogens and antigens, interleukin-2 production, and soluble interleukin-2 receptor production will add other important corregulatory dimensions. A single data entry and management system will facilitate exchange of information between investigators at BCM and UT and the NHLBI.